Extracorporeal blood circuits for use in an extracorporeal treatment of body fluids such as blood are known from practice. Prior to their first use, such blood circuits are regularly filled with a liquid in order to displace air contained therein. After termination of the treatment, they are regularly filled with a fluid in order to return blood present in the extracorporeal blood circuit upon termination of the treatment back to the vascular system of the patient.
One object of the present invention is to propose a new valve arrangement enabling short-circuiting the arterial and the venous line of the extracorporeal blood circuit, filling the blood circuit and/or emptying the said. Additionally, corresponding methods are to be proposed.
Thus, according to the present invention, there is proposed a valve arrangement which is suited and/or provided and/or configured for its use in an extracorporeal blood circuit, comprising at least one arterial blood line and at least one venous blood line. The valve arrangement comprises at least one first valve which is arranged in the arterial blood line, a second valve which is arranged in the venous blood line, a fourth valve which is arranged in a first arteriovenous connection line between the arterial blood line of the extracorporeal blood circuit and the venous line of the extracorporeal blood circuit as well as a fifth valve which is arranged in a second arteriovenous connection line between the arterial blood line and the venous blood line.
Alternatively or additionally to the afore-mentioned valves, the valve arrangement according to the present invention comprises a third valve which is arranged for establishing a fluid connection in a blood line between the arterial blood line and the venous blood line of the extracorporeal blood circuit or which is arranged for establishing a fluid connection directly between the arterial blood line and the venous blood line, preferably without a tube element being connected there between.
In turn additionally to some or all of the aforementioned valves or instead of the same, the valve arrangement according to the present invention comprises a sixth valve which is arranged between a blood treatment device or means, respectively, and an air venting or deflating or air dumping means or device, respectively, of the extracorporeal blood circuit.
The blood tubing set according to the present invention as well as the blood cassette according to the present invention comprise at least one valve arrangement according to the present invention.
The treatment apparatus according to the present invention is provided for extracorporeally treating medical fluids, in particular blood. It comprises at least one controlling device or means, respectively, as well as actuators that are provided and configured for controlling or regulating at least one valve arrangement according to the present invention.
Advantageous embodiments of the present invention are each subject matter of the dependent claims.
Embodiments according to the present invention can comprise some or all of the following features in an arbitrary combination.
In some embodiments according to the present invention, the blood treatment device is a blood filter.
In certain embodiments according to the present invention, the air venting device is a drip chamber or a venting site or a part thereof, respectively.
In some embodiments according to the present invention, the arterial blood line of the extracorporeal blood circuit is a line conducting blood with higher oxygen content during the blood treatment (as compared to the venous blood line which is conducting blood with lower oxygen content).
In certain embodiments according to the present invention, the arterial blood line of the extracorporeal blood circuit is a line which, during the blood treatment, conducts blood from the patient whereas the venous blood line conducts blood to the patient.
In some embodiments according to the present invention, the arterial blood line of the extracorporeal blood circuit is a line or patient line which, during the blood treatment, conducts blood between a patient connector and the blood filter. In certain embodiments according to the present invention, the venous blood line is a line or patient line which conducts blood between a drip chamber and a patient connector.
In some embodiments according to the present invention, the first and/or the second arteriovenous blood line is designed as a fluid connection, for example, as a tube segment, a line or the like, allowing blood to flow through from an arterial blood line to a venous blood line of the extracorporeal blood circuit, respectively, independently from the direction in which the flow takes place.
In certain embodiments according to the present invention, the valve arrangement additionally comprises at least one ventilation valve for venting the blood circuit, in particular by establishing a connection between an interior of the extracorporeal blood circuit and an exterior thereof, e.g., the atmosphere.
In some embodiments according to the present invention, some or all of the afore-mentioned valves are active valves.
An active valve in the sense of the present invention is in certain embodiments according to the present invention a valve which is, in particular exclusively, provided for active actuation, independently from the actuation being performed manually or by means of appropriate devices or means, respectively. In these embodiments, an active valve thus differs from a valve opening or closing in a self-actuating or automatic, respectively, manner such as, e.g., a non-return valve.
An active valve in the sense of the present invention is in certain embodiments according to the present invention a valve which is, in particular exclusively, controlled or actuated by a device such as, e.g., a controller.
In certain embodiments according to the present invention, the valve arrangement comprises a device for controlling or regulating the valve function of all or some of the aforementioned valves.
In some embodiments according to the present invention of the valve arrangement, the valve arrangement is designed and provided for use with a non-occluding pump for conveying the fluid to be treated, in particular blood.
In certain embodiments according to the present invention of the valve arrangement, at least the first, the second, the fourth and the fifth valve are present in a common support material. A support material in the sense of the present invention is in certain embodiments a single element or component, respectively, a smallest non-destructively available unit, a blood cassette, an adaptor or a device or means, respectively, generally provided for connecting arterial and venous patient lines or connectors or the like.
In certain embodiments, the valve arrangement according to the present invention comprises at least one recirculation adaptor or is at least partially part of such a recirculation adaptor. In these embodiments, the recirculation adaptor comprises at least four valves, in particular, the first, the second, the fourth and the fifth valve. In certain embodiments, the recirculation adaptor further comprises the third valve.
In some embodiments according to the present invention of the valve arrangement, at least the third valve is designed as a phantom valve.
A “phantom valve” as used herein can be a component comprising an actuator surface (for example, an actuator membrane) reachable by means of an actuator which can fulfill the function of a valve. Examples for appropriate phantom valves can be derived from the applications of the present applicant DE 10 2009 024 664.6 which has been deposited at the German Patent and Trademark Office on Apr. 23, 2009, DE 10 2009 024 468.9 which has been deposited at the German Patent and Trademark Office on Jun. 10, 2009 or DE 10 2009 012 632.5 which has been deposited at the German Patent and Trademark Office on Mar. 10, 2009, the entire contents of which are hereby each fully incorporated by way of reference.
In certain embodiments according to the present invention, the valve arrangement comprises sensors for measuring the arterial pressure in front of the filter means, e.g., a dialyzer, (“pre filter pressure”), for measuring the venous pressure downstream the air venting device, e.g., an air separation chamber, (“pressure return”), for measuring the optical density, for detecting the air bubbles present in a blood line interior of the arterial or the venous blood line (“air bubble detector”, or “ABD”) and the like as well as arbitrary combinations thereof. The sensors can be present in or at the arterial and/or the venous blood line. They can be present in or at the arterial and/or the venous leg of the extracorporeal blood circuit. The sensors can be designed as multi-sensors for measuring/detecting several of the afore-mentioned parameters.
In some embodiments according to the present invention, the valve arrangement comprises a device for controlling or regulating a flow difference which is generated by means of setting or operating a blood pump and/or a dialysate pump and/or appropriate means such as valves, throttles and the like, in particular in an intended manner.
In certain embodiments according to the present invention, the valve arrangement is designed in a blood cassette or is part of such a blood cassette or comprises such a blood cassette. Such a blood cassette can, for example, be designed as a cast part or an injection molded part. It can independently thereof be designed as a disposable.
In some embodiments according to the present invention of the valve arrangement, one, two or more valves are designed as being switchable as a segment of a rotatable or rotational element, respectively. Thereby, the respective rotatable elements can be designed as being actuable independently from each other or in a coupled manner, i.e. only in common.
In certain embodiments, the treatment apparatus according to the present invention is designed as an extracorporeal treatment apparatus, in particular as a dialyzing apparatus, particularly as a hemodialysis apparatus, a hemofiltration apparatus, a hemodiafiltration apparatus or as an apparatus for the adsorption, liver support therapy, apheresis, transfusion etc. It is particularly apt for use in methods in which the fluid is drawn from the patient and is returned back to the patient by means of different needles or accesses (the latter are known as double needle methods).
The object of the present invention is further solved by a method for handling an extracorporeal blood circuit, using a valve arrangement according to the present invention. The handling of the extracorporeal blood circuit can comprise or respectively consist of short-circuiting an arterial and a venous blood line of the extracorporeal blood circuit, filling the extracorporeal blood circuit and/or flushing sections or parts of the extracorporeal blood circuit while a flow disturbance is present or is not present in one of the blood lines of the extracorporeal blood circuit, as well as arbitrary combinations thereof.
In some embodiments, the method for handling according to the present invention serves for short-circuiting an arterial blood line and a venous blood line of an extracorporeal blood circuit by means of a valve arrangement according to the present invention by connecting the arterial blood line with the venous blood line by means of opening the third valve.
In some embodiments, the method for handling according to the present invention serves for filling or priming an extracorporeal blood circuit or parts thereof by means of a valve arrangement according to the present invention when using an occluding blood pump. This method can comprise the following steps—solitarily or in an arbitrary combination: connecting the extracorporeal blood circuit with an occluding blood pump; connecting a dialysate circuit with a dialysate pump; filling the dialysate circuit with fluid; conveying a flow by means of the blood pump in a direction opposite to the usual flow direction of an extracorporeal blood treatment; conveying a flow across the membrane of a filter of a blood treatment apparatus by means of the dialysate pump, wherein the flow is larger than the flow conveyed or generated by the blood pump, while the first and the second valve are open; opening a ventilation valve; stopping the dialysate pump or setting a balancing system to neutral balance and closing the ventilation valve; circulating the fluid by means of the blood pump within the extracorporeal blood circuit in usual flow direction while the first and the second valve are still open; removing air from the extracorporeal blood circuit by means of an air separation chamber by setting a positive balance, i.e. by generating a flow generated by means of the dialysate pump of larger than zero, in the balancing system while the ventilation valve is open.
According to the present invention, in some embodiments of the present invention, a “usual” flow direction is understood as the usual flow direction of an extracorporeal blood treatment.
Thereby, the usual flow direction of an extracorporeal blood treatment can be the direction in which the blood is flowing extracorporeally most of the time.
The usual flow direction of an extracorporeal blood treatment can be the direction in which the blood is flowing extracorporeally from the arterial vascular access of the patient by means of the arterial patient line or blood line and to the venous vascular access of the patient by means of the venous patient or blood line in a double needle method.
Thereby, the flows QD (dialysate) and QB (blood) can preferably be determined such that venting a blood line between a filter of a blood treatment apparatus and the air separation chamber and the arterial blood line and the venous blood line is achieved at the same time.
Furthermore, the afore-mentioned steps of stopping the dialysate pump or setting a balancing systems to neutral balance and closing the ventilation valve, circulating and removing air can hereby be performed for several times.
In some embodiments, the flow QD is to be understood as the dialysate flow out of the dialysate compartment of the dialyzer through the membrane into the blood compartment of the dialyzer.
In some embodiments according to the present invention, QD is thus to be differed from the entire flow of the dialysate which is pumped into the dialysate compartment of the dialyzer by means of the dialysate pump.
In certain embodiments according to the present invention the flow of the dialysate in front of and behind the dialyzer is balanced (e.g., by means of known balancing chambers, not shown in the figures).
Appropriate devices or means, respectively, and/or methods or processes or proceedings, respectively, can be used for balancing.
Balancing during an extracorporeal blood treatment can be of interest or importance in particular in embodiments in which a defined amount of excess water is to be removed from the patient, for example, during a dialysis.
In some embodiments according to the present invention, a “neutral balance” is understood such that the pressures and flows in front of and behind the dialysate compartment and in the blood compartment are set such that no flow QD of the dialysate is pressed through the membrane. This can, for example, be performed by completely stopping the dialysate pump. Stopping or completely stopping is, however, not mandatorily required herefor.
Thus, in certain embodiments, the fluid flow to the patient at a neutral balance is as high as the fluid flow away from the patient. The patient's weight can thus—substantially or completely—remain constant.
In some embodiments of the present invention, a “positive balance” is in contrary defined such that a flow QD of the dialysate is larger than zero, i.e., QD>0. When QD>0, dialysate passes through the membrane into the blood compartment. In other words, the pressures and flows in the dialysate system in front of and behind the dialysate compartment and in the blood compartment are set such that a flow QD of the dialysate is forced or compelled, respectively, out of the dialysate compartment through the membrane into the blood compartment.
In certain embodiments, at a positive balance, the fluid flow to the patient is thus higher than the fluid flow away from the patient. Thus, at a positive balance, the patient can be supplied with liquid.
The desired “balance” can be set, e.g., according to a predetermined program by the blood treatment apparatus's control.
Independently from setting a positive or a neutral balance, in some embodiments according to the present invention, qualitative ratios between QD and QB can be or will be predetermined for the single rinsing procedures. Based on such a ratio, the “balance” can, but does not have to, be influenced under certain circumstances. In certain embodiments according to the present invention, setting the ratio between QD and QB can serve for setting certain flows in the arterial and/or the venous line and the valve arrangement according to the present invention (also referred to as a “rinsing adaptor”).
According to the present invention, the method for handling can be or comprise filling the extracorporeal blood circuit or parts thereof when using a non-occluding blood pump. This method comprises at least one of the steps of: short-circuiting patient connectors; introducing or supplying, respectively, fluid from a dialysate circuit into the extracorporeal blood circuit by means of setting a positive balance; stopping the blood pump; closing a sixth valve, opening the first and the second valve as well as the ventilation valve; closing the third, fourth and fifth valve, if present; pressing fluid out of the dialysate compartment across the membrane of the filter onto the blood side of the filter; closing the first and the second valve; opening the sixth valve after having detected a fluid level in the air separation chamber; stopping the dialysate pump and/or setting the balancing system to a neutral balance; closing the ventilation valve; circulating the fluid within the extracorporeal blood circuit by means of the blood pump while the first and the second valve as well as the sixth valve are open; setting a positive balance in the balancing system (QD>0); opening the ventilation valve; and stopping the blood pump.
Some of these method steps can be performed for several times.
According to the present invention, the method for handling an extracorporeal blood circuit by means of the valve arrangement according to the present invention can be or comprise flushing an extracorporeal blood circuit or parts thereof by means of a valve arrangement according to the present invention, while no flow disturbance is present in one of the blood lines. The method then comprises at least one of the steps of: conveying a flow by means of the blood pump in a direction opposite to the usual flow direction while the blood lines are connected to the vascular access of the patient; conveying fluid by means of the dialysate pump out of the dialysate circuit with a flow being larger than the flow generated by means of the blood pump across the membrane of a filter of a blood treatment apparatus into the extracorporeal blood circuit; opening the first and the second valve, opening the sixth valve while the third, the fourth and the fifth valve and the ventilation valve are closed, as far as they are present; determining, by means of sensors, when or that the fluid displaces or has sufficiently displaced blood; controlling or regulating the blood return process according to the amount of the flow difference between the flow generated or conveyed by means of the dialysate pump and the flow generated or conveyed by means of the blood pump or by correspondingly switching the first and the second valve; stopping the non-occluding blood pump; switching the first and the second valve in order to induce or prompt, respectively, the blood return via a selected one of the blood lines.
According to the present invention, the method for handling an extracorporeal blood circuit can be or comprise flushing the extracorporeal blood circuit or parts thereof, while a flow disturbance is present in one of the blood lines. The method then comprises at least one of the steps of: conveying by means of the blood pump with a flow in a direction opposite to the usual flow direction, wherein the arterial blood line and/or the venous blood line are each connected with the respective vascular access of the patient; conveying fluid out of the dialysate circuit across the membrane of a filter of a blood treatment apparatus into the extracorporeal blood circuit by means of a dialysate pump with a flow that is larger than the flow generated by means of the blood pump; directing the entire flow to one of the two blood lines by correspondingly switching the first, the second, the third, the fourth and/or the fifth valve; switching the fifth valve and the sixth valve or adequately selecting the flow difference between the flow conveyed by means of the dialysate pump and the flow conveyed by means of the blood pump for achieving a flow through the arterial blood line or the venous blood line.
Moreover, in the method according to the present invention, a flow QD can be generated in the extracorporeal blood circuit by means of the dialysate pump while the blood pump does not convey or stagnates or is not overflown or flushed, respectively.
Furthermore, in certain embodiments of the method according to the present invention, the blood pump and the dialysate pump convey with the same pump flow rates wherein the blood pump preferably rotates or conveys, respectively, in reverse direction.
According to the present invention, the term “reverse” or “reverse direction”, respectively, is in connection with the direction of conveyance of the blood pump and/or of the dialysate pump to be understood as a direction opposite to the direction of conveyance of the respective pump in which the respective pump is predominantly conveying during a proceeding blood treatment or a direction opposite to the usual direction of conveyance of a proceeding blood treatment.
In certain embodiments, the method according to the present invention further comprises setting a positive balance wherein the flow conveyed by means of the dialysate pump is larger than the flow conveyed by means of the blood pump when using a non-occluding blood pump and/or switching the flow paths by means of the first to fifth valves as well as the sixth valve in order to flush the non-blocked blood lines.
All advantages achievable by means of the valve arrangement according to the present invention may undiminishedly also be obtained by the method according to the present invention and vice versa.
The object according to the present invention is further solved by a digital storage means in connection with corresponding hardware suited and/or provided therefor, a computer program product and a computer program. All advantages achievable by means of the method according to the present invention may undiminishedly also be obtained by means of the digital storage means according to the present invention, the computer program product according to the present invention and/or the computer program according to the present invention.
The digital storage means which can particularly be a disk, a CD or a DVD, a USB flash drive, a flash card, a SD card etc., preferably comprises electrically readable control signals which can interact with a programmable computer system such that the execution of the technical steps of the method according to the present invention is prompted or induced, respectively.
Thereby, all, a few or some of the automatically performed steps of the method according to the present invention may be prompted. The latter also applies for the computer program product and the computer program.
The computer program product preferably comprises a program code stored on a machine-readable storage means for prompting the execution of the automatically performable steps of the method according to the present invention when the program product is run on a computer.
The term “machine-readable storage means” as used herein refers to a storage or data means, respectively, containing data or information that are interpretable by software and/or hardware. The storage means can be a data storage means such as a disk, a CD, DVD, a USB flash drive, a flash card, a SD card and the like.
The computer program comprises a program code for prompting the execution of the automatically performable steps of the method according to the present invention when running the program on a computer.
Certain embodiments according to the present invention comprise one or more of the following advantages.
The present invention provides a valve arrangement by means of which venting and/or flushing an extracorporeal blood circuit is possible in an advantageously simple and technically less complex manner. The valve arrangement according to the present invention can advantageously also be used for a non-occluding blood pump which has hitherto not been possible for such pumps in the field of extracorporeal blood treatments. Therewith, some of the methods mentioned above can now advantageously also be used with non-occluding blood pumps.
By means of the third valve, the separation of air out of the extracorporeal blood circuit can advantageously be performed or facilitated. During the treatment, air can penetrate into the extracorporeal blood circuit. This air is usually detected by the protective system (air bubble detector) and has to be removed from the extracorporeal blood circuit. In conventional tubing systems, this is achieved manually.
By means of automated ventilation such as is possible by means of the present invention, the effort required herefore can advantageously be minimized. In some embodiments according to the present invention, the safety of the system can be increased. This can in particular be the case when, for the purpose of venting, blood is decoupled from the patient's blood system by means of the valve block or the recirculation adaptor, respectively, preferably by correspondingly switching the third valve. Hereby, blood being present extracorporeally can be recirculated within the extracorporeal blood circuit such that air is directly guided into the air separation chamber without reaching the patient or having to be directed through the capillary filter of, e.g., a dialyzing apparatus. This can be of particular advantage as air easily “accumulates” in the capillary filter or is disintegrated to micro-bubbles. Therefore, the third valve advantageously offers the possibility to direct air bubbles present to the air separation chamber (e.g., the venous drip chamber) by means of internal circulation or recirculation in or opposite to the usual flow direction of an extracorporeal blood treatment.
The third valve can advantageously offer the possibility to recirculate the blood within the cassette while the patient is decoupled. Thereby, the patient can also be connected, if he wants to, which can advantageously save time and effort.
A recirculation within the extracorporeal blood circuit can offer the advantage that blood present extracorporeally can be further pumped across the filter in a case of, e.g., an access problem (e.g., in case of a high return pressure). In this way, in certain embodiments, it can advantageously be avoided that such an access problem will result in a stop of the flow through the extracorporeal blood circuit. This may advantageously allow for significantly reducing the risk of blood coagulation, for example, in the filter.
Furthermore, the present invention can in some of its embodiments advantageously contribute for enabling further circulation across the filter in alarm situations in which the blood pump would usually necessarily be stopped. In this way, it can advantageously be ensured for the patient not to suffer a loss of blood due to discarding the coagulated system, to achieve a more effective treatment time and to omit an optionally necessary change of the system.
When the third valve is opened for recirculation or internal circulation, respectively, in some embodiments according to the present invention, the sixth valve and, in case of air separation, the ventilation valve will be opened—if present, respectively. The first, the second, the fourth and the fifth valve should each be closed.
The sixth valve can advantageously be used for enabling filling or priming, respectively, both the arterial blood line and the venous blood line when using a non-occluding blood pump. Therefore, the arterial blood line is at first filled retrogradely, that means opposite to the usual flow direction, by means of the dialysate pump while the sixth valve is closed and, after opening the sixth valve, the venous blood line is filled anterogradely, that means in the usual flow direction, by means of the blood pump.
In case of an occluding blood pump, the sixth valve can advantageously be used for rinsing the arterial blood line upstream.
Besides the use described above, the sixth valve is analogously also used for flushing (blood return) the extracorporeal blood circuit.
The position of the sixth valve between the filter and the drip chamber can advantageously contribute for performing air separation, filling and emptying in an intended manner.
In case of need, the flow direction can advantageously be reversed or inversed, respectively, in the arterial and the venous blood line (flow reversion) by means of the first and the fourth as well as the second and the fifth valve. Thereby, the direction of the blood flow in the filter can be maintained. In this way, the counter flow principle can advantageously be maintained. Flow reversion can be of particular advantage in case of flow problems, e.g., by sucking the catheter. In certain embodiments according to the present invention, flow reversion can be induced by the dialyzing machine automatically or in a self-actuating manner (by means of corresponding devices). This may, for example, be the case if an insufficient flow is detected.
Additionally, the valve arrangement according to the present invention offers the possibility to prompt a blood return in case of a unilateral occlusion of a blood line and/or of a catheter or a needle.
The use of active valves such as provided in certain embodiments of the present invention can advantageously allow for maintaining the counter flow principle as well.
Moreover, active valves can advantageously contribute for enabling unilaterally flushing and/or unilaterally returning blood through the arterial (“access”) blood line or the venous (“return”) blood line of the tubing system. In this way, it can advantageously be possible to perform an automated diagnosis of the access problems (clotting/sucking the catheter) as a flow can advantageously be generated in one or even in both directions (in and opposite to the usual flow direction) in the two blood lines (the arterial and the venous blood line) in a respectively separate or independent manner.